临地铁结构物桩基施工技术研究

Study on Construction Technology About pile Foundation of adjacent Metro structure

为分析桩基施工对临近地铁结构物变形影响效应,采用Midas GTS软件建立三维模型,并结合FLAC3D进行数值模拟计算分析,对桥梁桩基施工过程地铁结构物安全性进行研究。以南宁市清川立交工程为研究实例,对桥梁桩基施工引起的地铁结构沉降与变形进行研究,采用地层-结构模型,通过Midas GTS和FLAC3D数值模拟计算分析,得到不同工况施工过程中地铁盾构区和场站区周边土体及其结构物的沉降变形特征,对既有地铁结构的安全性进行了评价,得到竖向位移远远大于水平位移,确定了桩基施工影响范围和施工方案,制订既有1号线地铁结构的变形控制标准和保护措施,为南方类似不良地质条件下跨结构物桩基施工提供了可靠的数据支持,具有重要指导意义。

In order to analyze the effect of pile foundation construction on the deformation of adjacent subway structure,a three-dimensional model is established by using Midas GTS software,and the safety of subway structure during the construction of bridge pile foundation is studied by numerical simulation and analysis combined with FLAC3D.Taking Qingchuan Interchange Project at Nanning City as an example,the settlement and deformation of subway structure caused by bridge pile foundation construction are studied.The stratigraphic structure model is used to calculate and analyze the settlement and deformation of subway structure by Midas GTS and FLAC3D numerical simulation.The settlement and deformation characteristics of the soil and its structures around the ground iron shield and the field station are obtained during the construction under different working conditions.The safety of the existing subway structures is evaluated.It is obtained that the vertical displacement is far greater than the horizontal displacement,the influence range and construction scheme of pile foundation are determined,and the deformation control standard and protection measures of the existing subway structure of Line 1are determined,which provides reliable data support for the construction of cross-structure pile foundation under similar geological conditions,and it has important guiding significance.